WO2020059386A1

WO2020059386A1 - Catheter assembly

Info

Publication number: WO2020059386A1
Application number: PCT/JP2019/032440
Authority: WO
Inventors: 石田昌弘
Original assignee: テルモ株式会社
Priority date: 2018-09-19
Filing date: 2019-08-20
Publication date: 2020-03-26
Also published as: JPWO2020059386A1; US20210196925A1; JP7356441B2; CN112672783B; CN112672783A

Abstract

This catheter assembly (10A) is provided with: a catheter (12a); and an inner needle (16) which is passed through the catheter (12a). The catheter (12a) is provided with a plurality of parts along the axial direction which can be distinguished from each other. Each of the plurality of parts has a different hardness to the adjacent parts.

Description

Catheter assembly

The present invention relates to a catheter assembly that punctures a blood vessel and indwells it, for example, when performing infusion or the like on a patient.

カテーテル Conventionally, a catheter assembly used for performing infusion or the like on a patient is known. This type of catheter assembly includes a hollow catheter, a catheter hub fixed to the proximal end of the catheter, a hollow inner needle inserted into the catheter and having a sharp tip at the distal end, and a proximal end of the inner needle. (See, for example, JP-A-2008-43445). When using the catheter assembly, after the inner needle and each tip of the catheter are pierced into the skin and blood vessel of the living body, the catheter is advanced to the inner needle, so that the catheter is inserted into the blood vessel for a predetermined length. .

The present invention has been made in connection with the above-mentioned conventional technology, and has as its object to provide a catheter assembly capable of easily imparting a catheter with desired characteristics according to the purpose of treatment or use.

One embodiment of the present invention includes a catheter and an inner needle inserted through the catheter, wherein the catheter has a plurality of portions that can be distinguished from each other along an axial direction, and the plurality of portions are A catheter assembly in which adjacent portions have different hardnesses.

ADVANTAGE OF THE INVENTION According to the catheter assembly of this invention, since several parts provided in the catheter differ in the hardness of adjacent parts, the catheter can easily provide desired characteristics according to the treatment purpose and application. Can be granted.

It is a perspective view of a catheter assembly concerning a 1st embodiment of the present invention. It is sectional drawing of the front-end | tip part of a catheter assembly. It is operation | movement explanatory drawing of a catheter assembly. It is sectional drawing of the front-end | tip part of the catheter assembly which concerns on 2nd Embodiment of this invention. It is sectional drawing of the front-end | tip part of the catheter assembly which concerns on 3rd Embodiment of this invention. It is sectional drawing of the front-end | tip part of the catheter assembly which concerns on 4th Embodiment of this invention. It is sectional drawing of the front-end | tip part of the catheter assembly which concerns on 5th Embodiment of this invention. It is sectional drawing of the front-end | tip part of the catheter assembly which concerns on 6th Embodiment of this invention. It is sectional drawing of the front-end | tip part of the catheter assembly which concerns on 7th Embodiment of this invention.

Hereinafter, preferred embodiments of the catheter assembly according to the present invention will be described with reference to the accompanying drawings.

カテーテル The catheter assembly 10A shown in the initial state in FIG. 1 is applied when performing infusion or blood transfusion on a patient (living body), and is punctured and detained in the patient's body to construct an introduction portion for a drug solution or the like. The catheter assembly 10A may be configured as a catheter that is longer than a peripheral venous catheter (eg, a central venous catheter, a PICC, a midline catheter, etc.). Note that the catheter assembly 10A may be configured as a peripheral venous catheter. Further, the catheter assembly 10A is not limited to a venous catheter, and may be configured as an arterial catheter such as a peripheral arterial catheter.

As shown in FIG. 1, the catheter assembly 10A includes a catheter 12a, a catheter hub 14 for fixedly holding the catheter 12a, a hollow inner needle 16 removably inserted into the catheter 12a, and the inner needle 16 fixed thereto. It has a needle hub 18 for holding and a catheter operation member 20 mounted on the catheter hub 14. The inner needle 16 may be a solid needle.

In the initial state before use, the catheter assembly 10A has a multi-tube structure (multi-tube portion) in which the catheter 12a and the inner needle 16 are sequentially stacked.

The catheter 12a has flexibility, and has a lumen 13 formed therein. The lumen 13 is formed to have a diameter capable of accommodating the inner needle 16 and allowing a medical solution, blood, or the like to flow. The distal end of the catheter 12a is reduced in diameter in order to reduce puncture resistance, and in the initial state of the catheter assembly 10A, the inner surface of the catheter 12a and the outer surface of the inner needle 16 are in close contact with each other at the reduced diameter portion. The length of the catheter 12a is not particularly limited and can be appropriately designed according to the application and various conditions. For example, the length is set to about 14 to 500 mm, or about 30 to 400 mm, or about 76 to 200 mm. Is set.

基 The proximal end of the catheter 12a is fixed to the distal end inside the catheter hub 14. The catheter member 17 is constituted by the catheter 12a and the catheter hub 14.

The catheter hub 14 is exposed on the patient's skin in a state where the catheter 12a is inserted into a blood vessel, is adhered by a tape or the like, and is left together with the catheter 12a. The catheter hub 14 is formed in a cylindrical shape that tapers in the distal direction.

The constituent material of the catheter hub 14 is not particularly limited. For example, a thermoplastic resin such as polypropylene, polycarbonate, polyamide, polysulfone, polyarylate, methacrylate-butylene-styrene copolymer, or polyurethane may be used.

中空 A hollow portion 15 is provided inside the catheter hub 14 so as to communicate with the lumen 13 of the catheter 12a and through which the infusion solution can flow. The hollow portion 15 may house a hemostatic valve, a plug, or the like (not shown) that prevents backflow of blood when the inner needle 16 is punctured and enables infusion when the connector of the infusion tube is inserted.

The inner needle 16 is formed as a rigid hollow tube capable of piercing the skin of a living body, and is disposed so as to penetrate the lumen 13 of the catheter 12a and the hollow portion 15 of the catheter hub 14. The inner needle 16 is formed to have a longer overall length than the catheter 12a, and a sharp tip 16a is provided at the tip thereof. A lumen that penetrates the inner needle 16 in the axial direction is provided inside the inner needle 16, and the lumen communicates with the distal end opening of the inner needle 16.

構成 As a constituent material of the inner needle 16, for example, a metal material such as stainless steel, aluminum or an aluminum alloy, titanium or a titanium alloy, a hard resin, ceramics, and the like can be given.

The needle hub 18 has a needle holding member 22 fixed to the proximal end of the inner needle 16 and a housing 24 to which the needle holding member 22 is fixed and extends along the inner needle 16 and the catheter 12a. In the initial state, the catheter assembly 10A accommodates a part of the multi-tube portion, the catheter hub 14, and the catheter operation member 20 in the housing 24. Although the resin material constituting the needle holding member 22 and the housing 24 is not particularly limited, for example, the materials listed for the catheter hub 14 can be appropriately selected. Note that the needle holding member 22 and the housing 24 may be integrally formed.

Since the needle hub 18 holds the inner needle 16 in the needle holding member 22, when the needle hub 18 is moved in the proximal direction with respect to the catheter 12a, the inner needle 16 is also moved with the movement of the needle hub 18. 12a is moved in the proximal direction.

The catheter operation member 20 is mounted on the catheter hub 14. For this reason, when the catheter operation member 20 is advanced relatively to the needle hub 18, the catheter member 17 advances relatively to the inner needle 16. The catheter operation member 20 has a hub mounting portion 20a detachably mounted on the catheter hub 14, and an operation plate portion 20b extending from the hub mounting portion 20a in the distal direction along the catheter 12a. Note that, in the catheter assembly 10A, the catheter operation member 20 may not be provided.

The catheter assembly 10A has a support member 26 provided on the distal end side of the housing 24 to support the lower side of the catheter 12a held by the catheter operation member 20. The support member 26 is rotatably attached to an arrangement recess 24 a provided at the tip of the housing 24. The distal end portion of the catheter operation member 20 and the support member 26 constitute a deflection suppressing mechanism 27.

When the inner needle 16 and the catheter 12a puncture the skin, the distal end of the catheter operation member 20 supports the catheter 12a from above and the support member 26 supports the catheter 12a from below, so that the catheter 12a and the inner needle 16 bend. Is suppressed. When the catheter operation member 20 comes out of the housing 24, the support member 26 is rotated toward the outside of the housing 24 by being pushed by the hub mounting portion 20a, so that the catheter hub 14 is detached from the housing 24 in the distal direction. be able to. Note that the support member 26 may not be provided.

As shown in FIG. 2, the catheter 12 a has a contact portion 30 on at least a part of the inner peripheral surface thereof, which is in close contact with the outer peripheral surface of the inner needle 16 over the entire circumference. The contact portion 30 is provided on the inner peripheral surface of the distal end portion of the catheter 12a. A flow path for flashback confirmation (hereinafter, referred to as “flashback flow path 32”) is formed between the catheter 12 a and the inner needle 16 and closer to the base end than the close contact portion 30. The flashback channel 32 extends to the proximal opening of the catheter 12a.

The catheter 12a has a plurality of portions that can be distinguished from each other along the direction of the axis a of the catheter (hereinafter, referred to as “axial direction”). The plurality of portions are different in hardness (elastic modulus) between adjacent portions. In the first embodiment, the catheter 12a has, as the plurality of portions, a catheter body 34 that forms a main part of the catheter 12a, and a flexible portion 38 provided at a distal end of the catheter body 34. Therefore, the distal end of the catheter 12a becomes more flexible toward the distal end. The flexible portion 38 is exposed from the housing 24 (FIG. 1).

The catheter body 34 occupies most of the entire length of the catheter 12a. For this reason, the distal end of the catheter body 34 is located near the distal end of the catheter 12a. The catheter body 34 and the flexible portion 38 are made of a flexible resin material.

The flashback channel 32 is formed between the inner peripheral surface of the catheter body 34 and the outer peripheral surface of the inner needle 16. At least the catheter body 34 of the catheter body 34 and the flexible portion 38 has transparency so that flashback can be confirmed.

The catheter 12a is supported by the support member 26 (FIG. 1) at the position of the catheter body 34 (the catheter body 34 is supported by the support member 26). Accordingly, the catheter 12a can be reliably supported, and the sliding resistance when the catheter 12a is advanced can be reduced. Moreover, since the portion supported by the support member 26 (FIG. 1) is located on the base end side of the interface 42 between the catheter body 34 and the flexible portion 38, the catheter 12a slides on the support member 26. Peeling of the interface 42 due to this can be prevented.

It is preferable that the catheter body 34 does not easily swell compared to the flexible portion 38. Thus, during steam sterilization (autoclave sterilization) or ethylene oxide gas sterilization in the manufacturing process of the catheter assembly 10A, the axial distance between the foremost position of the inner needle 16 and the foremost position of the catheter 12a is set to a desired size. And the variation between products can be reduced.

Examples of the constituent material of the catheter body 34 include fluorine resins such as polytetrafluoroethylene (PTFE), ethylene / tetrafluoroethylene copolymer (ETFE), and perfluoroalkoxy fluororesin (PFA), and olefins such as polyethylene and polypropylene. Or a mixture thereof, polyurethane, polyester, polyamide, polyether nylon resin, a mixture of an olefin resin and an ethylene / vinyl acetate copolymer, and the like. The durometer hardness of the catheter body 34 is, for example, less than D70.

The flexible portion 38 includes the distal end of the catheter 12a. The flexible portion 38 is more flexible than the catheter body 34. That is, the elastic modulus k1 of the catheter body 34 and the elastic modulus k2 of the flexible portion 38 have a relationship of k1> k2.

The flexible portion 38 has a straight portion 38a having a constant outer diameter along the axial direction, and a tapered portion 38b extending from the straight portion 38a in the distal direction and decreasing in outer diameter in the distal direction. The inner peripheral surface of the flexible portion 38 is in liquid-tight contact (fit) with the outer peripheral surface of the inner needle 16 over the entire circumference.

It is preferable that at least the flexible portion 38 of the catheter body 34 and the flexible portion 38 has X-ray contrast. Thus, for example, when the catheter 12a is disconnected in a blood vessel, the location of the catheter 12a that has been disconnected and left in the blood vessel can be easily confirmed by X-rays. The contrast layer in the case where the flexible portion 38 has contrast properties may be provided in any form of, for example, a stripe, an intermediate layer in a radial direction, or the whole.

Examples of the constituent material of the flexible portion 38 include various rubber materials such as natural rubber, butyl rubber, isoprene rubber, butadiene rubber, styrene-butadiene rubber, silicone rubber, polyurethane, polyester, polyamide, olefin, and styrene. And various thermoplastic elastomers such as a thermoplastic elastomer or a mixture thereof.

In the catheter 12a, a catheter body single region 40A in which only the catheter body 34 is present among the catheter body 34 and the flexible portion 38, and a flexible portion single region 40B in which only the flexible portion 38 is present in the catheter body 34 and the flexible portion 38, The catheter body 34 and the mixed area 40C in which the flexible part 38 exists are arranged in the axial direction. In the catheter 12a shown in FIG. 2, an interface 42 between the catheter body 34 and the flexible portion 38 is formed in a tapered shape inclined at a substantially constant angle with respect to the axis a of the catheter 12a.

The catheter main body unit region 40A is a portion of the catheter main body 34 that is located on the base end side of the most proximal end of the flexible portion 38.

The 部 flexible portion single region 40B is a portion of the 部 exible portion 38 that is located on the distal end side of the distal end portion of the catheter body 34. The length L1 in the axial direction of the flexible portion single region 40B is set, for example, to 0.3 to 5.0 mm, preferably to 0.4 to 2.0 mm, and more preferably to 0.5 to 0.9 mm. Is set. The hardness of the flexible portion 38 (flexible portion single region 40B) is, for example, A80 to D67 at 23 ° C., and preferably D53 to D64. The flexible portion 38 in the illustrated example is joined to the catheter body 34. By setting the axial length and hardness of the flexible portion single region 40B in the above ranges, it is possible to suppress the tip (the flexible portion 38) of the catheter 12a from being turned up at the time of puncturing. Further, it is possible to suitably suppress the catch on the back wall of the blood vessel when the catheter 12a is inserted. Further, the collapse of the distal end of the catheter 12a during blood suction can be suppressed.

The mixed region 40C is a portion where the catheter body 34 and the flexible portion 38 are laminated in the radial direction. The axial length L2 of the mixed area 40C is set, for example, to 1 to 5 mm, and preferably to 2 to 3 mm.

では In the catheter 12a shown in FIG. 2, the interface 42 between the catheter main body 34 and the flexible portion 38 is inclined so as to approach the axis a (center) of the catheter 12a toward the distal end. Therefore, in the mixed region 40C, the flexible portion 38 exists outside the catheter body 34.

カテーテル Instead of the above-described configuration having the interface 42, the catheter 12a may be formed so as to become softer toward the distal end by changing the blending amount of materials having different hardnesses in the axial direction. In this case, the extrusion molding may be performed while changing the extrusion speed of different materials. Alternatively, the content of the plasticizer at the distal end of the catheter 12a may be increased. In this case, a plasticizer may be applied to the distal end of the catheter 12a.

On the inner needle 16, on the side opposite to the blade surface 16 b, there is provided a back cut portion 16 c which is continuous with the needle tip 16 a and is inclined in the direction opposite to the blade surface 16 b with respect to the axis of the inner needle 16.

The inner needle 16 is provided with an introduction path 44 that communicates with the flashback channel 32 and introduces blood into the flashback channel 32. In FIG. 2, an introduction path 44 indicated by a solid line is a side hole 44 A that radially penetrates a wall portion of the inner needle 16. 2, the introduction path 44 may be a groove 44B extending in the axial direction on the outer peripheral surface of the inner needle 16.

で In the initial state of the catheter assembly 10A shown in FIG. 2, at least the proximal end 44a of the introduction path 44 is provided on the distal end side of the distal end portion of the catheter main body unit region 40A. The entire side hole 44A shown in FIG. 2 is provided on the distal end side of the distal end portion of the catheter main body unit region 40A. More specifically, the base end 44a of the introduction path 44 is provided on the distal end side with respect to the axial center position Pc1 of the flexible portion single region 40B. The proximal end 44a of the introduction path 44 is provided more distally than the proximal end of the tapered portion 38b of the flexible portion 38. The side hole 44A is entirely provided at a position facing the inner peripheral surface of the tapered portion 38b of the flexible portion 38. In another aspect, the base end 44 a of the introduction path 44 (or the entire side hole 44 A) may be provided at a position facing the inner peripheral surface of the straight portion 38 a of the flexible portion 38.

Regarding the position of the introduction path 44 in relation to the close contact portion 30, in the initial state of the catheter assembly 10 A shown in FIG. 2, at least the proximal end 44 a of the introduce path 44 (side hole 44 A, groove 44 B) Are also provided on the base end side. The side hole 44 A is entirely provided on the base end side of the contact portion 30.

Next, the operation of the catheter assembly 10A configured as described above will be described.

使用 In using the catheter assembly 10A shown in FIG. 1, a puncturing operation for puncturing the catheter assembly 10A into the skin of a patient is performed. In the puncturing operation, a user (a doctor, a nurse, or the like) punctures the skin toward a puncture target blood vessel while holding the housing 24 and pressing the distal end of the catheter assembly 10A against the patient. Thereby, each distal end of the inner needle 16 and the catheter 12a is punctured into the skin.

Next, while fixing the position of the needle hub 18 (housing 24), the user operates the catheter operating member 20 in the distal direction to advance the catheter member 17 (the catheter 12a and the catheter hub 14). Thereby, the catheter 12a is inserted to a target position in the blood vessel.

Next, the user pulls the housing 24 in the proximal direction while holding the positions of the catheter operation member 20 and the catheter member 17. Thereby, the catheter member 17 and the catheter operation member 20 completely come out of the housing 24, and the inner needle 16 is withdrawn from the catheter 12a in the proximal direction.

Next, the catheter operation member 20 is removed from the catheter hub 14. Thereby, the catheter member 17 is left in the patient. The catheter operation member 20 may be left attached to the catheter hub 14 depending on the user's preference.

Next, a connector of an infusion tube (not shown) is connected to the proximal end side (the proximal end portion of the catheter hub 14) of the catheter member 17 from which the inner needle 16 has been removed, and an infusion agent (medical solution) from the infusion tube to the patient is connected. ) Is administered.

In this case, the catheter assembly 10A according to the present embodiment has the following effects.

According to the catheter assembly 10A, the distal end portion of the catheter body 34 is provided with a flexible portion 38 that is more flexible than the catheter body 34, as shown in FIG. Therefore, as shown in FIG. 3, even when the puncture angle, which is the angle between the central axis of the blood vessel 50 to be punctured and the central axis of the inner needle 16 to be punctured, is large, the distal end of the catheter assembly 10A is punctured into the skin S. When the catheter 12a is advanced to insert the catheter 12a into the blood vessel 50 later, the distal end of the catheter 12a is prevented from being caught on the blood vessel rear wall 50a, which is the blood vessel wall of the blood vessel 50 opposite to the puncture site. It is possible to do.

That is, when the catheter 12a is advanced as shown in FIG. 3, the flexible portion 38 comes into contact with the blood vessel posterior wall 50a and is easily deformed by being pushed by the blood vessel posterior wall 50a. It is possible to prevent the hook 50a from being caught. Accordingly, it is possible to prevent the catheter 12a from being unable to be inserted into the blood vessel 50, and prevent the distal end of the catheter 12a from damaging the blood vessel rear wall 50a.

As shown in FIG. 2, a flashback flow path 32 is formed between the catheter 12a and the inner needle 16, and the inner needle 16 communicates with the flashback flow path 32, and the flashback flow path 32 An introduction path 44 for introducing blood is provided. The proximal end 44a of the introduction path 44 is provided on the distal end side of the central portion Pc1 in the axial direction of a portion of the flexible portion 38 located on the distal end side of the distal end portion of the catheter body 34. Therefore, the flashback of blood can be confirmed more quickly.

において In the catheter assembly 10B according to the second embodiment shown in FIG. 4, the catheter 12b has a plurality of portions that can be distinguished from each other along the axial direction. The plurality of portions are different in hardness (elastic modulus) between adjacent portions. In the second embodiment, the catheter 12b is provided as the plurality of portions, the catheter body 34, the catheter tip 62 including the distal end of the catheter 12b, and the catheter body 34 and the catheter tip 62. And a catheter intermediate portion 64.

The catheter distal end 62 is configured similarly to the flexible portion 38 in the first embodiment. Therefore, the catheter distal end portion 62 is configured to be more flexible than the catheter body 34. The catheter intermediate portion 64 has a straight shape in which the outer diameter of the outer peripheral surface of the catheter 12b is constant along the axial direction. In another aspect, the catheter intermediate portion 64 may have a tapered portion in which the outer diameter of the outer peripheral surface of the catheter 12b decreases toward the distal direction.

In one aspect, the catheter intermediate section 64 has a different hardness from the catheter body 34 and the catheter tip section 62. The catheter intermediate section 64 may be configured to be more flexible than the catheter body 34 or may be configured to be harder than the catheter body 34. The catheter intermediate portion 64 may be configured to be more flexible than the catheter distal end portion 62, or may be configured to be harder than the catheter distal end portion 62. The catheter intermediate portion 64 may be configured to have a hardness between the catheter main body 34 and the catheter distal end portion 62, or may be configured to be harder than both the catheter main body 34 and the catheter distal end portion 62. It may be configured to be more flexible than both of the catheter tip portions 62.

In another aspect, the catheter tip portion 62 may be configured to have the same hardness as the catheter body 34 or may be configured to be harder than the catheter body 34.

界面 The interface (first interface 65a) between the catheter body 34 and the catheter intermediate portion 64 is formed in a tapered shape that is inclined so as to approach the axis a of the catheter 12b toward the distal end. The interface (second interface 65b) between the catheter distal end portion 62 and the catheter intermediate portion 64 is formed in a tapered shape that is inclined so as to approach the axis a of the catheter 12b toward the distal end. The inclination angle of the first interface 65a with respect to the axis a of the catheter 12b and the inclination angle of the second interface 65b with respect to the axis a of the catheter 12b may be the same or different.

で In the initial state of the catheter assembly 10B, at least the proximal end 44a of the introduction path 44 is provided on the distal end side of the catheter body 34 at the most distal end. The entire side hole 44 A is provided on the distal end side of the most distal end portion of the catheter body 34. The proximal end 44a of the introduction path 44 is a portion (a region having a length L3 in FIG. 4) of the region where the catheter distal end portion 62 and the catheter intermediate portion 64 are located on the distal end side with respect to the most distal end portion of the catheter main body 34. ) Is provided on the tip side with respect to the axial center position Pc2. The entire side hole 44 A is provided on the distal end side of the most distal end portion of the catheter intermediate portion 64.

As described above, in the catheter assembly 10B, the plurality of portions provided on the catheter 12b have different hardnesses between adjacent portions. For this reason, similarly to the first embodiment, it is possible to easily impart desired characteristics to the catheter 12b according to the purpose of treatment and the purpose of use.

The catheter 12b is provided as a plurality of portions provided along the axial direction, the catheter main body 34, a catheter distal end portion 62 including the distal end portion of the catheter 12b, and the catheter main body 34 and the catheter distal end portion 62. Catheter intermediate portion 64. With this configuration, the catheter main body 34 and the catheter intermediate portion 64 have different hardnesses, and the catheter distal end portion 62 and the catheter intermediate portion 64 have different hardnesses. Therefore, it is easy to impart more complicated characteristics to the catheter 12b. .

The proximal end 44a of the introduction path 44 is located closer to the distal end than the axial center position Pc2 of a portion of the combined region of the catheter distal end portion 62 and the catheter intermediate portion 64, which is located on the distal end side of the distal end portion of the catheter body 34. It is provided in. With this configuration, the flashback of blood can be confirmed more quickly.

Note that, of the second embodiment, the same or similar operations and effects as those of the first embodiment can be obtained for portions common to the first embodiment.

において In the catheter assembly 10C according to the third embodiment shown in FIG. 5, the catheter 12c has a plurality of portions that can be distinguished from each other along the axial direction. The plurality of portions are different in hardness (elastic modulus) between adjacent portions. In the third embodiment, the catheter 12c is provided as the plurality of portions, the catheter body 34, the catheter tip 66 including the distal end of the catheter 12c, and the catheter 12 between the catheter body 34 and the catheter tip 66. And a catheter intermediate section 68. The magnitude relationship between the hardness of the catheter body 34, the catheter tip 66, and the catheter intermediate section 68 in the catheter 12c is determined by the relationship between the catheter body 34, the catheter tip 62, and the catheter in the catheter 12b (FIG. 4) of the second embodiment. The hardness may be set in the same manner as the hardness relationship between the intermediate portion 64 and the intermediate portion 64.

The catheter 12c has a contact portion 70 on at least a part of the inner peripheral surface thereof, which is in close contact with the outer peripheral surface of the inner needle 16 over the entire circumference. In the contact portion 70, both the catheter distal end portion 66 and the catheter intermediate portion 68 are in close contact with the inner needle 16. Specifically, the inner peripheral surface 66a of the catheter distal end portion 66 is tightly fitted (fitted) to the outer peripheral surface of the inner needle 16 over the entire circumference. Further, the inner peripheral surface 68a of the catheter intermediate portion 68 is tightly fitted (fitted) with the outer peripheral surface of the inner needle 16 over the entire circumference.

先端 The distal end of the catheter intermediate section 68 has a smaller outer diameter than the proximal end of the catheter intermediate section 68. The outer diameter of the proximal end of the catheter intermediate section 68 is larger than the maximum outer diameter of the catheter distal end 66. The proximal end of the catheter intermediate portion 68 is separated from the outer peripheral surface of the inner needle 16 over the entire circumference. The distal end of the catheter intermediate portion 68 is located proximal to the distal end of the catheter distal end 66. The proximal end 44a of the introduction path 44 is provided closer to the proximal end than the most proximal end of a portion of the catheter intermediate portion 68 that comes into close contact with the outer peripheral surface of the inner needle 16 (a portion forming the contact portion 70).

As described above, in the contact portion 70, both the catheter distal end portion 66 and the catheter intermediate portion 68 are in close contact with the inner needle 16. With this configuration, an appropriate fitting force between the inner needle 16 and the catheter 12c can be obtained.

Note that, in the third embodiment, the same or similar operations and effects as those of the first embodiment or the second embodiment can be obtained for portions common to the first embodiment or the second embodiment.

において In the catheter assembly 10D according to the fourth embodiment shown in FIG. 6, the catheter 12d has a plurality of portions that can be distinguished from each other along the axial direction. The plurality of portions are different in hardness (elastic modulus) between adjacent portions. Specifically, the catheter 12d includes, as the plurality of portions, a catheter body 72 and a flexible portion 74 provided at a distal end of the catheter body 72.

The catheter main body 72 includes a first main body 72a including the distal end of the catheter 12d, a second main body 72b adjacent to the proximal end of the first main body 72a, and an adjacent proximal end of the second main body 72b. A third main body 72c, a fourth main body 72d adjacent to the proximal end of the third main body 72c, a fifth main body 72e adjacent to the proximal end of the fourth main body 72d, and a fifth main body And a sixth body portion 72f adjacent to the base end side of 72e.

The first main body 72a has a tapered shape in which the outer diameter decreases toward the distal end. The second main body 72b has a straight shape whose outer diameter is constant along the axial direction. The radial thickness of the second main body 72b (the thickness of the peripheral wall constituting the second main body 72b) is smaller than the maximum radial thickness of the flexible part 74. The third main body 72c has a tapered shape in which the outer diameter decreases toward the distal end. The fourth main body 72d has a tapered shape in which the outer diameter and the inner diameter decrease toward the distal end. The fifth main body 72e has a shape in which the outer diameter decreases and the inner diameter is constant toward the distal end. The sixth body portion 72f has a straight shape in which the outer diameter and the inner diameter are constant along the axial direction.

The flexible portion 74 includes the distal end portion of the catheter 12d and is configured to be more flexible than the catheter body 72. The maximum outer diameter of the flexible portion 74 is smaller than the maximum outer diameter of the catheter main body 72 (the outer diameter of the sixth main body 72f). A catheter body 72 is interposed between the flexible portion 74 and the inner needle 16 over the entire length of the flexible portion 74. Therefore, the inner peripheral surface of the flexible portion 74 is not in close contact with the outer peripheral surface of the inner needle 16.

The catheter 12d has a contact portion 76 that is in close contact with the outer peripheral surface of the inner needle 16 over the entire periphery. In the contact portion 76, only the inner peripheral surface of the catheter body 72 of the catheter body 72 and the flexible portion 74 is in close contact with the outer peripheral surface of the inner needle 16.

において In the catheter assembly 10E according to the fifth embodiment shown in FIG. 7, the catheter 12e has a plurality of portions that can be distinguished from each other along the axial direction. The plurality of portions are different in hardness (elastic modulus) between adjacent portions. Specifically, the catheter 12e includes, as the plurality of portions, a catheter body 80 and a flexible portion 82 provided at a distal end of the catheter body 80.

The catheter main body 80 includes a first main body 80a including the most distal end of the catheter main body 80, a second main body 80b adjacent to the proximal end of the first main body 80a, and a proximal main end of the second main body 80b. It has an adjacent third main body 80c and a fourth main body 80d adjacent to the base end of the third main body 80c.

The first main body 80a has a tapered shape in which the outer diameter decreases toward the distal end. The second main body portion 80b has a tapered shape in which the outer diameter decreases toward the distal end. The third main body 80c has a shape in which the outer diameter is constant along the axial direction and the inner diameter decreases as it goes toward the distal end. The fourth main body 80d has a straight shape in which the outer diameter and the inner diameter are constant along the axial direction.

The inclination angle α of the outer peripheral surface of the first main body portion 80a with respect to the axis a of the catheter 12e is smaller than the inclination angle β of the outer peripheral surface of the second main body portion 80b with respect to the axis a of the catheter 12e. In another embodiment, the inclination angle α of the outer peripheral surface of the first main body portion 80a with respect to the axis a of the catheter 12e may be the same as the inclination angle β of the outer peripheral surface of the second main body portion 80b with respect to the axis a of the catheter 12e.

The flexible portion 82 is configured to be more flexible than the catheter body 80. The flexible portion 82 includes a first flexible portion 82a including the distal end portion of the flexible portion 82, a second flexible portion 82b adjacent to the proximal side of the first flexible portion 82a, and a proximal side of the second flexible portion 82b. And a third flexible portion 82c adjacent thereto. The first flexible portion 82a has a tapered shape whose outer diameter decreases as it goes toward the distal end. The second flexible portion 82b has a straight shape whose outer diameter is constant in the axial direction. The third flexible portion 82c has a tapered shape in which the outer diameter decreases toward the distal end.

において In the catheter assembly 10F according to the sixth embodiment shown in FIG. 8, the catheter 12f has a plurality of portions that can be distinguished from each other along the axial direction. The plurality of portions are different in hardness (elastic modulus) between adjacent portions. Specifically, the catheter 12f has a catheter body 86 and a flexible portion 88 provided at the distal end of the catheter body 86 as the plurality of portions.

The catheter main body 86 includes a first main body 86a including the distal end of the catheter main body 86, a second main body 86b adjacent to the proximal end of the first main body 86a, and a proximal main end of the second main body 86b. And a third main body 86c adjacent thereto.

The first main body 86a has a tapered shape in which the outer diameter decreases toward the distal end. The second main body portion 86b has a tapered shape in which the outer diameter and the inner diameter decrease toward the distal direction. The third main body 86c has a straight shape whose outer diameter and inner diameter are constant along the axial direction.

The flexible portion 88 is configured to be more flexible than the catheter body 86. The flexible portion 88 includes a first flexible portion 88a including the most distal portion of the flexible portion 88, a second flexible portion 88b adjacent to the proximal side of the first flexible portion 88a, and a proximal side of the second flexible portion 88b. And a third flexible portion 88c adjacent thereto. The first flexible portion 88a has a tapered shape whose outer diameter decreases as it goes toward the distal end. The second flexible portion 88b has a straight shape whose outer diameter is constant along the axial direction. The third flexible portion 88c has a tapered shape in which the outer diameter and the inner diameter decrease toward the distal end.

傾斜 The inclination angle θ1 of the outer peripheral surface of the first main body portion 86a with respect to the axis a of the catheter 12f is the same as the inclination angle θ2 of the outer peripheral surface of the first flexible portion 88a with respect to the axis a of the catheter 12f. In another aspect, the inclination angle θ1 of the outer peripheral surface of the first main body portion 86a with respect to the axis a of the catheter 12f is larger than the inclination angle θ2 of the outer peripheral surface of the first flexible portion 88a with respect to the axis a of the catheter 12f.

In the catheter assembly 10G according to the seventh embodiment shown in FIG. 9, in the initial state, at least the proximal end 44a of the introduction path 44 in the catheter 12g is provided on the distal end side of the distal end portion of the catheter main body unit region 40A. ing. The whole side hole 44A shown in FIG. 9 is provided on the distal end side of the distal end portion of the catheter main body unit region 40A. More specifically, the base end 44a of the introduction path 44 is provided at the same position in the axial direction as the central position Pc1 in the axial direction of the flexible portion unit region 40B. The proximal end 44a of the introduction path 44 is provided more distally than the proximal end of the tapered portion 38b of the flexible portion 38. The side hole 44A is entirely provided at a position facing the inner peripheral surface of the tapered portion 38b of the flexible portion 38. In another aspect, the base end 44a of the introduction path 44 (or the entire side hole 44A) may be provided at a position facing the inner peripheral surface of the straight portion 38a of the flexible portion 38.

The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention.

Claims

A catheter,
An inner needle inserted through the catheter,
The catheter has a plurality of portions that can be distinguished from each other along the axial direction,
The catheter assembly, wherein the plurality of portions have different hardnesses between adjacent portions.
The catheter assembly according to claim 1,
The catheter has a catheter body as the plurality of portions, and a flexible portion provided at a distal end portion of the catheter body,
The catheter assembly, wherein the flexible portion includes a distal end of the catheter and is more flexible than the catheter body.
The catheter assembly according to claim 2,
A flow path for flashback confirmation is formed between the catheter and the inner needle,
The inner needle communicates with the flow path, and an introduction path for introducing blood into the flow path is provided.
A catheter assembly, wherein a proximal end of the introduction path is provided at a distal end side of an axially central position of a portion of the flexible portion that is located at a distal end side of a distal end portion of the catheter body.
The catheter assembly according to claim 2,
A flow path for flashback confirmation is formed between the catheter and the inner needle,
The inner needle communicates with the flow path, and an introduction path for introducing blood into the flow path is provided.
A catheter assembly, wherein the proximal end of the introduction path is provided at the same position in the axial direction as the central position in the axial direction of a portion of the flexible portion located on the distal end side of the distal end portion of the catheter body.
The catheter assembly according to claim 1,
The catheter, as the plurality of portions, a catheter body, a catheter tip portion including the distal end of the catheter, and a catheter intermediate portion provided between the catheter body and the catheter tip portion, a catheter Assembly.
The catheter assembly according to claim 5,
A flow path for flashback confirmation is formed between the catheter and the inner needle,
The inner needle communicates with the flow path, and an introduction path for introducing blood into the flow path is provided.
The proximal end of the introduction path is provided at a position closer to the distal end than the axial center position of a portion of the combined region of the catheter distal end portion and the catheter intermediate portion that is located more distally than the most distal end portion of the catheter body. A catheter assembly.
The catheter assembly according to claim 5,
The catheter, at least a portion of the inner peripheral surface, has a contact portion that is in close contact with the outer peripheral surface of the inner needle,
The catheter assembly, wherein at the contact portion, both the catheter distal end portion and the catheter intermediate portion are in close contact with the inner needle.